Ecological benefits of the three-north shelter forest project were evaluated based on total value calculated from the data regarding project status

which was estimated using remote sensing monitoring and ground truthing in Zhongyang County

Shanxi Province.An ecological benefit evaluation map of the threenorth shelter forest project was acquired using GIS

providing a basis for project evaluation and ecological compensation.The results show that the three-north shelter forest project in Zhongyang County has improved ecological environment significantly

resulted in annual average ecological benefit per unit area of 40 807.05yuan/(hm2·a)

and annual total ecological benefit of 3.08×109 yuan/a.As of the spatial distribution

the sites located in the earthy-rocky mountainous area developed a large number of natural secondary forests

suggesting a better environmental conditions than in the loess area.Annual average ecological benefits per unit area in the earthy-rocky mountainous and in loess area were 42 800.98and 37 342.20yuan/(hm2 ·a)

respectively.In terms of vegetation type

annual average ecological benefit per unit area of the forests (coniferous

broadleaved

and coniferous and broadleaved mixed)was greater than that of shrub

as of 44 618.59and 37 414.95yuan/(hm2·a)

respectively